...I'm not sure what politics/personality things came into the decision by GHWB not to share the info with Carter. It's noteworthy to see the apparent hostility between the two whenever they get together (i.e. at Obama's inauguration)...
There is also apparent 'hostility' between Carter & Clinton, which was also noted most recently at Obama's inauguration.
With regard to Bush 41, I had heard him refer during an Imus interview (a few weeks prior to Inaugural) to Carter's many negative comments about G.W. Bush which he he noted was not the best way to get on his good side. A father will stand by his son, no matter what age, no matter what profession.
I hear Carter & Gerald Ford eventually became good friends, and he did give Ford's eulogy so I suppose it's nice that Carter didn't manage to alienate
EVERY one of his contemporaries.
Apple
